Field of the Invention
The present technology relates to an optical characteristic measurement apparatus which measures optical characteristics of a measurement target object and an optical system included therein.
Description of the Background Art
A microspectroscope has been known as one example of an optical characteristic measurement apparatus which measures optical characteristics of a measurement target object. The microspectroscope outputs optical characteristics such as a reflectance, an index of refraction, a coefficient of extinction, and a thickness of the measurement target object by subjecting light from any measurement target object to spectroscopy. Japanese Patent Laying-Open No. 2008-286583 discloses as one example of the microspectroscope, an optical characteristic measurement apparatus with improved accuracy in measurement of optical characteristics, in which focusing on a measurement target object can more readily be achieved.
The optical characteristic measurement apparatus disclosed in Japanese Patent Laying-Open No. 2008-286583 has a structure of a microscope of a type referred to as a finite tube. In contrast, a structure of a microscope referred to as an infinite tube type has been known. Japanese Patent Laying-Open No. 11-249027 discloses an autofocus microscope which can automatically adjust a position of focus on an observed sample as a configuration adopting such an infinite tube type microscope.